I have an old wired home alarm system that has one of the window sensors wiring damaged and its inaccessible.
The old sensor would be closed when window is closed and open when window is opened.
I want to replace this with a Shelly Window Sensor and Shelly Relay - the sensor will trigger the Relay condition where the relay's switched contacts are connected to the alarm control board in place of the original wired sensor.
The problem is that the relay must be closed when the window is closed and open when the Sensor Triggers it.
I recognize I can set it up like that, but what it means is that the relay will be virtually constantly enabled and only turned off when the window opens.
A Normally-closed relay would be just perfect (I have submitted product suggestion for that - I'm sure there are lots of other applications for this)
In the meantime, what is concern over lifetime reliability, if the Shelly 1 is set up to be in that predominantly enabled state?
Is there anything else I'm missing to achieve what I want to do? I suppose a second (non smart) relay driven by the Shelly could be employed to provide the correct logic but it's a bit messy. i.e. the Shelly 1 output is only when the sensor is triggered open and the closed switch